1. Field of the Invention
This invention relates to computer systems and, more particularly, to backup and restoration of data within computer systems.
2. Description of the Related Art
Many business organizations and governmental entities rely upon applications that access large amounts of data, often exceeding many terabytes of data, for mission-critical applications. Numerous different types of storage devices, potentially from multiple storage vendors, with varying functionality, performance and availability characteristics, may be employed in such environments.
Any one of a variety of factors, such as system crashes, hardware storage device failures, software defects, or user errors (e.g., an inadvertent deletion of a file) may potentially lead to data corruption or to a loss of critical data in such environments. In order to recover from such failures, various kinds of backup techniques may be employed. For example, in some storage environments, file-level replication may be employed, where a complete copy of the set of files in one or more file systems at a primary host may be created at a secondary host. If the primary host fails, or if the file system at the primary host becomes corrupted or unavailable, the files may be recovered or restored by copying from the replica.
However, simply restoring contents of storage objects such as files or directories may be insufficient for a desired level of recovery from certain types of failures. For example, if a primary host whose files are backed up by a file replication mechanism fails, users may desire that the configuration state of the primary host also be restored, along with the file data. Unfortunately, some types of system configuration information, as well as other information appropriate for backup such as application-generated or user-supplied information, may not typically be available or stored in a format recognized by the replication mechanism, and as a result, may not typically be backed up along with the storage object data. For example, in storage environments employing file-based replication as the backup mechanism, configuration information related to network-based file shares may not be stored in a file format accessible to the file replication engine, and various elements of system state information may also be stored in data structures other than files, or may have to be collected from portions of several files. Requiring separate backup mechanisms to be implemented for different sources of configuration information and any other non-file structured information that may be needed for restoration may not be a cost-effective solution in many storage environments. In addition, in some storage environments, especially environments where disk-based backups are implemented, transparent access to some or all of the backup versions of storage objects may be provided to end users. That is, end users may be permitted to access backup versions of storage objects directly, without administrative intervention. In such environments, when accessing the backup versions, some end users may expect to make use of configuration settings (such as file share settings) similar to those of the primary host.